Ferdinand II[1] (10 March 1452 – 23 January 1516), called the Catholic, was King of Sicily from 1468 and King of Aragón[2] from 1479 until his death. As a consequence of his marriage to Isabella I, he was King of Castilejure uxoris as Ferdinand V from 1474 until her death in 1504. He was recognised as regent of Castile for his daughter and heir, Joanna, from 1508 until his own death. In 1504, after a war with France, he became King of Naples as Ferdinand III, reuniting Naples with Sicily permanently and for the first time since 1458. In 1512, he became King of Navarre by conquest.

Ferdinand is today best known for his role in inaugurating the discovery of the New World, since he and Isabella sponsored the first voyage of Christopher Columbus in 1492. That year he also fought the final war with Granada which expunged the last Islamic state on Iberian soil, thus bringing to a close the centuries-long Reconquista. At his death he was succeeded by Joanna, who co-ruled with her son, Charles V, over all the Iberian kingdoms save Portugal.

The completion of the Reconquista was not the only significant act performed by Ferdinand and Isabella in that year. In March 1492, the monarchs issued the Edict of Expulsion of the Jews, also called the Alhambra Decree,[7] a document which ordered all Jews either to be baptised and convert to Christianity or to leave the country.[8] That document was signed with the defeated Moorish Emir of Granada Muhammad XII, who had bargained for the Muslims of Spain to be left alone.[citation needed] It allowed Mudéjar Moors (Islamic) and conversoMarrano Jews to stay, while expelling all unconverted Jews from Castile and Aragon (most Jews either converted or moved to Islamic lands of North Africa and the Ottoman Empire). 1492 was also the year in which the monarchs commissioned Christopher Columbus to find a westward maritime route for access to Asia, which resulted in the Spanish arrival in the Americas.

In 1494 the Treaty of Tordesillas divided the entire world beyond Europe between Portugal and Castile (Spain) for conquest and dominion purposes – by a north–south line drawn down the Atlantic Ocean.

Ferdinand violated the 1492 Alhambra Decree peace treaty in 1502 by dismissing the clearly guaranteed religious freedom for Mudéjar Muslims. Ferdinand forced all Muslims in Castile and Aragon to convert, conversoMoriscos, to Catholicism, or else be expelled. Some of the Muslims who remained were mudéjar artisans, who could design and build in the Moorish style. This was also practised by the Spanish inquisitors on the conversoMarrano Jewish population of Spain. The main architect behind the Spanish Inquisition was King Ferdinand II, whom was ironically of converso heritage (or perhaps because of it, he may have been embittered by being the great-grandson of Fadrique's mistress).[9][10] Ferdinand destroyed over ten thousand Arabic manuscripts in Granada alone, burning them.

The latter part of Ferdinand's life was largely taken up with disputes with successive Kings of France over control of Italy, the so-called Italian Wars. In 1494, Charles VIII of France invaded Italy and expelled Alfonso II, who was Ferdinand's first cousin once removed and stepson of Ferdinand's sister, from the throne of Naples. Ferdinand allied with various Italian princes and with Emperor Maximilian I to expel the French by 1496 and install Alfonso's son, Ferdinand, on the Neapolitan throne. In 1501, following the death of Ferdinand II of Naples and accession of his uncle Frederick, Ferdinand signed an agreement with Charles VIII's successor, Louis XII, who had just successfully asserted his claims to the Duchy of Milan, to partition Naples between them, with Campania and the Abruzzi, including Naples itself, going to the French and Ferdinand taking Apulia and Calabria. The agreement soon fell apart and, over the next several years, Ferdinand's great general Gonzalo Fernández de Córdoba fought to take Naples from the French, finally succeeding by 1504.

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"The King of France complains that I have twice deceived him. He lies, the fool; I have deceived him ten times and more." --Ferdinand the Catholic.[11]

After Isabella I's death in 1504, her kingdom went to their daughter Joanna. Ferdinand II served as the latter's regent during her absence in the Netherlands, ruled by her husband Archduke Philip. Ferdinand attempted to retain the regency permanently, but was rebuffed by the Castilian nobility and replaced with Joanna's husband, who became Philip I of Castile. After Philip's death in 1506, with Joanna supposedly mentally unstable, and her and Philip's son, the future Emperor Charles V, only six years old, Ferdinand resumed the regency, ruling through Francisco Jiménez de Cisneros, the Chancellor of the Kingdom. Charles I (to later become Holy Roman Emperor Charles V) became the King of Aragon in 1516, with his mother Joanna as Queen in name, upon Ferdinand's death.

In the 16th century his son Alonso de Aragón, found a hidden study under Ferdinand's palace containing over 400 documents written by Ferdinand. In these documents Ferdinand explained his general outlook on political power, and his true goals behind all his decisions during life as the King of Castile and Aragon. Also through these documents, Ferdinand wrote that "during times of very complicated decision making he blindfolded himself to concentrate on the true matter of a situation, and not let other things 'cloud his judgment'."[citation needed]

In 1508 war resumed in Italy, this time against the Republic of Venice, which all the other powers with interests on the Italian peninsula, including Louis XII, Ferdinand II, Maximilian, and Pope Julius II joined together against as the 'League of Cambrai'. Although the French were victorious against Venice at the Battle of Agnadello, the League of Cambrai soon fell apart, as both the Pope and Ferdinand II became suspicious of French intentions. Instead, the 'Holy League' was formed, in which now all the powers joined together against Louis XII and France.

In November 1511 Ferdinand II and his son-in-law King Henry VIII of England signed the Treaty of Westminster, pledging mutual aid between the two against Navarre and France ahead of the Castilian invasion of Navarre as of July 1512. After the fall of Granada in 1492, he had manoeuvred for years to take over the throne of the Basque kingdom, ruled by Queen Catherine of Navarre and King John III of Navarre, also lords of Béarn and other sizeable territories of the Pyrenees and western Gascony. Ferdinand annexed Navarre first to the Crown of Aragon, but later, under the pressure of Castilian noblemen, to the Crown of Castile. The Holy League was generally successful in Italy, as well, driving the French from Milan, which was restored to its Sforza dukes by the peace treaty in 1513. The French were successful in reconquering Milan two years later, however.

Ferdinand and Isabella established a highly effective sovereignty under equal terms. They utilised a prenuptial agreement to lay down their terms. During their reign they supported each other effectively in accordance to his joint motto of equality: "Tanto monta (or monta tanto), Isabel como Fernando", ("They amount to the same, Isabel and Ferdinand"). Isabella and Ferdinand's achievements were remarkable: Spain was united, or at least more united than it ever was, the crown power was centralised, at least in name, the reconquista was successfully concluded, the groundwork for the most dominant military machine of the next century and a half was laid, a legal framework was created, the church reformed. Even without the benefit of the American expansion, Spain would have been a major European power. Columbus' discovery set the country on the course for the first modern world power.

During the reign of Ferdinand and Isabella, Spain pursued alliances through marriage with Portugal, Habsburg Austria, and Burgundy. Their first-born daughter Isabella was married to Alfonso of Portugal, and their first-born son John was married to Margaret of Austria. However, the deaths of these children, and the death of Isabella, altered the succession plan forcing Ferdinand to yield the government of Castile to Philip of Habsburg the husband of his second daughter Joanna.[13]

In 1502, the members of the Aragonese Cortes gathered in Zaragoza, and Parliaments of the Kingdom of Valencia and the Principality of Catalonia in Barcelona, as members of the Crown of Aragon, swore an oath of loyalty to their daughter Joanna as heiress, but Alonso de Aragón, Archbishop of Saragossa, stated firmly that this oath was invalid and did not change the law of succession which could only be done by formal legislation by the Cortes with the King.[14][15] So, when King Ferdinand died on 23 January 1516, his daughter Joanna inherited the Crown of Aragon, and his grandson Charles became Governor General (regent).[16] Nevertheless, the Flemish wished that Charles assume the royal title, and this was supported by his paternal grandfather the Holy Roman Emperor Maximilian I and by Pope Leo X. Consequently, after Ferdinand II's funeral on 14 March 1516, Charles I was proclaimed King of Castile and of Aragon jointly with his mother. Finally, the Castilian Regent, Cardinal Jiménez de Cisneros accepted the fait accompli, and the Castilian and Aragonese Cortes paid homage to him[17] as King of Aragon jointly with his mother.[18]

Ferdinand's grandson and successor Charles, was to inherit not only the Spanish lands of his maternal grandparents, but the Habsburg and Burgundian lands of his paternal family, which would make his heirs the most powerful rulers on the continent and, with the discoveries and conquests in the Americas and elsewhere, of the first truly global Empire.

John (1478–1497), Prince of Asturias (1478–1497). He married Margaret of Habsburg (daughter of King Maximilian I). He died of tuberculosis and his posthumous child with Margaret was stillborn.

Joanna I (1479–1555), Princess of Asturias (1500–1504), Queen of Castile (1504–1555), Queen of Aragon (1516–1555). She married Philip I(Philip the handsome) (son of the Emperor Maximilian I); and was the mother of King Charles I of Spain (also known as Charles V as Holy Roman Emperor). Ferdinand made her out to be mentally unstable and she was incarcerated by her father, and then by her son, in Tordesillas for over 50 years. Her grandson, Philip II of Spain, was crowned in 1556.